I can't access amazon prime this evening

I am sorry for the trouble you're having with the Amazon Prime app this evening. That 'something went wrong' message can certainly be a disruption to your night. 

You can often fix app-specific errors without restarting your whole box. Press the Xfinity button on your remote, go to Settings (gear icon) > Apps & Menu > Refresh App Data. This specifically re-syncs third-party apps like Amazon Prime.

If the app refresh doesn't work, unplug the power cord from the back of your Xfinity box, wait 30 seconds, and plug it back in. This forces the box to download the latest software updates and can resolve intermittent 'something went wrong' errors.
Let me know if this help @user_c39czk.